Spectroscopic Characterization of Edges in Transition Metal Dichalcogenide Metastructures

Abstract

Two-dimensional materials have proven to show a very broad spectrum of physical phenomena for the past decades, offering a very important scientific playground, both under an experimental and theoretical point of view. While the family of Transition Metal Dichalcogenides (TMDCs) has overcome most of the problems that prevented graphene to consolidate as a reliable material for a scalable integrated circuit implementation, they still face their own challenges regarding device-to-device variability, and requirements for industry-scalable dimensions. The next step in the understanding of two-dimensional materials is the study of the physics taking place at the edges, which can be very different from its bulk counterpart, these differences ultimately coming from the symmetry breaking in the crystal structure and its consequences on the electronic properties. In this context, this thesis is focused on the characterization of these one-dimensional defects that can be produced in a new kind of metastructures taking place on different TMDC multilayers, with very high-quality in their crystal symmetry and optoelectronic properties. The project will start with production of these physical systems, followed by their characterization via optical and mechanical means, in particular Raman spectroscopy, Second Harmonic Generation (SHG), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). This complete vision coming from different corners of the characterization will enlighten the growth process of these metastructures, testing their reliability as a system where the understanding of edge physics can be promoted and developed.